Reznikoff says he is not allowed to discuss the series — which has made minor celebrities of authenticators — but he "never claimed to be an expert in entertainment." He also says other experts on the show still consult with him on items; Harrison says Reznikoff is no longer involved.

Human error is inevitable, and neither company makes any claim to the contrary. Yet both seem to permit mistakes that lack any reasonable explanation.

In 2007, a FOX Philadelphia news crew attended a memorabilia show at which JSA set up a booth to evaluate autographs, including those produced by baseball player Sal Bando, who was sitting just a few tables away.

Courtesy Steve Sterpka

PSA provided a letter of authenticity endorsing the Lindbergh signature in May 2008. They reversed course when it was asked to evaluate the Lindbergh again over a year later. This time, the autograph was deemed a likely fake.

"That was a former employee of mine," Spence says of the Bando auditor. "I believe he was caught offguard. I wasn't in the building at the time. They sort of blindsided him with the whole thing.

"I hear that over and over again. No one wants to hear about the good we've done. When someone brings that up — if that's the worst thing they can point to, I'm doing pretty well."

It is not necessarily the worst thing. In 2011, Heritage Auctions offered a letter signed by boxer Thomas Sayers that was endorsed by both JSA and PSA. When boxing historians pointed out that Sayers was virtually illiterate — he had signed a document with an "X" the following year — the auction listing was corrected to reflect that PSA and JSA both believed it to be genuine but could no longer offer certificates "due to a lack of exemplars."

But if no exemplars were available, historians reasoned, what did they compare the signature to in the first place?

Spence says he cannot recall the Sayers incident. Heritage sold the letter for $10,755.

Another Heritage auction, for a 1939 Baseball Hall of Fame induction program, featured a signature by slugger Nap "Larry" Lajoie. It was endorsed by PSA and JSA, despite the likelihood that it was executed while Lajoie was either intoxicated or forgot how to sign his own name. More likely, an inept forger made a mistake, putting a third "R" in his nickname to spell "Larrry." It sold for $41,000.

Then came the instance when PSA authenticated a souvenir letter of surrender signed by Nazi Karl Dönitz after Hitler's death gave him the keys to the Reich. PSA erroneously read the signature as being that of Chester Nimitz, a United States admiral who presumably would not be in a position to surrender German forces, nor in any position to sign a commemorative letter dated 1976. Nimitz died in 1966.

Orlando asserts that no system is perfect, but he is unwilling to offer specifics, growing particularly agitated at the mention of Sterpka. "I don't like the nature of your questions," he says, declining to answer any more.

None of these mistakes appears to have slowed business. A cursory eBay search on any given day will reveal more than 200,000 items bearing a PSA or JSA stamp. As the world's largest auction destination, eBay even cautions its buyers that autographs or memorabilia not endorsed by the two companies "may not be authentic."

Officially, eBay's reach has helped to legitimize its expertise. Unofficially, the former head of eBay's memorabilia-fraud division thinks PSA and JSA "suck."

"Of all the things I've said, they chose the least eloquent thing to quote," sighs John Gonzales, eBay's director of calculated fraud. Until 2012, Gonzales was in charge of overseeing memorabilia on the site. His 2010 comment, part of an e-mail to a dealer, was leaked online. Four years later, his opinion hasn't wavered.

EBay has no formal relationship with either company. But Gonzales often asked PSA lead authenticator Grad to review suspicious items.

"I took him at his word," Gonzales says. But when Grad would look at JSA items and disagree with their opinion, Gonzales found it odd: If authentication was bound by strict rules of signature patterns and careful analysis, why would the two companies diverge?

"It told me," he says, "that it was more art than science."

A baseball signed by Walter Johnson and approved by JSA was priced at $80,000 before being removed after experts unaffiliated with PSA or JSA raised concerns. Another ball bearing 1920s left-fielder Goose Goslin's autograph — offered for $29,999 — had to be taken down for the same reason.

Though Gonzales maintains that PSA's Grad is "a total expert" — an opinion shared by Pawn Stars operator Harrison, who still uses Grad on his show — he believes the sheer volume of submissions makes it difficult to maintain any reasonable level of quality control.

"A lot of times, they will just go through stuff so fast they won't have time to review it properly," he says. "It should be a [letter] of opinion, not authenticity."

Gonzales was soon faced with a choice. If he ditched the companies altogether, he would essentially be winding the clock back to 1999, when forgers ran unchecked.

"I contemplated getting rid of them," he says. "The relationship is difficult to justify. On their best day, they're inept. But I came to the conclusion that they're the lesser of two evils. It's chaos otherwise."